OnionValidator: a dumb plugin for validating onion peers

setup.py

@@ -16,6 +16,7 @@ EXTRAS_REQUIRE = {
     'prctl': ['python_prctl'],  # Named threads
     'qrcode': ['qrcode'],
     'sound;platform_system=="Windows"': ['winsound'],
+    'tor': ['stem'],
     'docs': [
         'sphinx',  # fab build_docs
         'graphviz',  # fab build_docs
@@ -129,6 +130,9 @@ if __name__ == "__main__":
         ext_modules=[bitmsghash],
         zip_safe=False,
         entry_points={
+            'bitmessage.nodes.validator': [
+                'onion = pybitmessage.plugins.validator_onion [tor]'
+            ],
             'bitmessage.gui.menu': [
                 'address.qrcode = pybitmessage.plugins.menu_qrcode [qrcode]'
             ],

src/plugins/test_validator_onion.py

@@ -0,0 +1,31 @@
+import unittest
+
+from pybitmessage.state import Peer
+
+try:
+    from validator_onion import OnionValidator
+    validator_onion = True
+except ImportError:
+    validator_onion = False
+
+
+@unittest.skipIf(not validator_onion, 'OnionValidator is not available')
+class TestOnionValidator(unittest.TestCase):
+    """Test case for OnionValidator"""
+    @classmethod
+    def setUpClass(cls):
+        cls.check = OnionValidator()
+
+    def test_valid(self):
+        """Ensure validator returns True for valid nodes"""
+        # not onion node
+        self.assertTrue(self.check(Peer('5.45.99.75', 8444)))
+        # default onion node
+        self.assertTrue(self.check(Peer('quzwelsuziwqgpt2.onion', 8444)))
+
+    def test_invalid(self):
+        """Ensure validator returns False for invalid hostnames"""
+        # is not base32
+        self.assertFalse(self.check(Peer('test.onion', 8444)))
+        # no descriptor
+        self.assertFalse(self.check(Peer('aaaaaaaaaaaaaaaa.onion', 8444)))

src/plugins/validator_onion.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+
+import base64
+
+import stem
+from stem.control import Controller
+
+
+class OnionValidator(object):
+    """Validation plugin for onion nodes"""
+    def __init__(self):
+        try:  # TODO: deal with authentication
+            self.controller = Controller.from_port()
+            self.controller.authenticate()
+        except (stem.SocketError, stem.connection.AuthenticationFailure):
+            raise ValueError  # do not load this if controller is not available
+
+    def _validate_onion(self, addr):
+        """Check the .onion address validity"""
+        try:
+            base64.b32decode(addr, True)
+        except TypeError:
+            return False
+
+        if not self.controller:
+            return True
+
+        try:
+            self.controller.get_hidden_service_descriptor(addr)
+        except stem.DescriptorUnavailable:
+            return False
+
+        return True
+
+    def __call__(self, node):
+        """Filter check for .onion addresses validation"""
+        addr = node.host
+        try:
+            addr, dom = addr.split('.')
+        except ValueError:
+            return True
+        return self._validate_onion(addr) if dom == 'onion' else True
+
+
+connect_plugin = OnionValidator()